Glad to hear he's home again and even happier to know he's been properly diagnosed, so you can get a handle on everything and have a good treatment plan in place for preventative measures.
My daughter had severe asthma as a child which resulted in many a hospital stay at the beginning. However, early treatment with steroids, inhalers, a home nebulizer and use of a peak flow meter helped prevent complications such as pneumonia and collapsed lungs and allowed us to keep it under control for the most part. I can truthfully say her quality of life wasn't affected terribly; in fact, she became very athletic and thankfully the condition subsided considerably as she grew. Now, in her mid 20s, she needs only the occasional puff of ventolin when it's very humid or very cold.
I know how scary it is when they're so small and obviously in distress, but I'm sure you'll feel much more at ease once you've discussed it with the pediatrician. Give him a hug from me